Traditionalist Christians sometimes argue that the title Lord, reportedly given to Jesus by his followers, proves that they believed him to be God incarnate. According to this argument:
- Jesus’s followers addressed him as "Lord," as did various supplicants . Paul’s epistles likewise refer to Jesus as Lord.
- The Greek word used in the New Testament — kyrios or kurios — translated into English as Lord, is the same Greek word used in the Septuagint (the translation of the Hebrew Bible into Greek) as an alternative name for Yahweh, the LORD God.
- Therefore, the argument goes, Jesus’s followers and supplicants, and Paul the apostle, were necessarily proclaiming that Jesus was the LORD God in the flesh.
This argument is very big stretch. There's a more plausible explanation.
Kyrios as a heteronym?
You might remember that heteronyms are words used to signify different, sometimes conceptually-related, meanings: Bow, a bow and arrow, versus a bow knot, versus a bow in a river; or minute, a comparatively-short interval of time, versus a brief memorandum, versus an adjective meaning very small.
In the Greek New Testament, the term kyrios appears to be such a heteronym, used to name:
- the owner of the vineyard in the Parable of the Workers (Matt. 20.8);
- the master who beat the disobedient servant (Luke 20.42-47);
- the father who sent his sons to the vineyard (Matt. 21.30);
- Jesus, addressed by the Samaritan woman at the well who did not know him (John 4.11; she addresses him as kyrie, rendered by the NIV as "sir");
- an angel of God (Acts 10.4, likewise addressed as kyrie).
(Hat tip: Murray J. Harris, Slave of Christ: A New Testament Metaphor for Total Devotion to Christ, at p. 88; a Google Books excerpt with a more-detailed discussion is available at http://goo.gl/jE1qr.)
Fortunately, we don't need to figure out the precise meaning of the term kyrios in Greek. Nor need we worry about whether Jesus' followers and supplicants addressed him in Greek or in Aramaic.
Our task is simpler: We want to assess whether, when people addressed Jesus as "Lord," it was generally understood that they were hailing hailing him as Yahweh, the LORD God.
As a thought experiment, let’s assume the traditionalists are right on this point.
Calling Jesus “God” would surely have led to trouble — which didn't happen
It seems highly implausible that Jesus’s Jewish followers and supplicants, some of whom were strangers to him, would have addressed him as the LORD God; that would clearly have been regarded by others as blasphemy. Let's remember the Gospel accounts of how volatile the Judean crowds could be: Some crowds were hostile to Jesus (Matt 13.57), even ready to lynch him (Luke 4.28–29). It seems extremely plausible that the crowds surrounding Jesus would have reacted furiously if they had heard him being addressed as the LORD God; their fury likely would have been directed not just against the blasphemers, but against Jesus himself as well.
It also seems likely that the chief priests and Pharisees would have arrested Jesus if his followers had hailed him as the LORD God. The Gospels recount that chief priests were looking for a reason to take Jesus out of circulation ; blasphemy by his followers would have been as good a reason as any.
But nothing in the Gospels suggests anyone ever got angry about Jesus being addressed as "Lord." When they got angry at him (see the citations above), their anger didn’t stem from his being addressed as the LORD God.
The logical conclusion is that when Jesus’s followers and supplicants called him "Lord," no one imagined that they were calling him the LORD God.
So, the traditionalist Christian argument referred to at the beginning of this post just doesn't hold water.
 For example: The man with leprosy (Matt 8.2). The centurion with the paralyzed servant (Matt 8.6). The blind men whose eyes Jesus touched (Matt 9.28). The Canaanite woman with the demon-possessed daughter (Matt 15.22). The father whose son suffered seizures (Matt 17.15). The blind men sitting by the roadside (Matt 20.30).
 E.g., Matt 12.14, 22.15; Mark 12.12, 14.1; Luke 6.11, 11.53, 20.19.